1. Field of the Invention
This invention relates to bone drills and, more particularly, to a unique, retractable, tubular shield apparatus and method for enclosing a bone drill, the shield having a sharpened point for engagement with the bone to both aid in the alignment of the bonedrill and to preclude the bone drill from skidding across the bone surface upon commencement of the drilling operation.
2. The Prior Art
Various medical procedures involve drilling a hole in bone. For example, the procedure for the repair of ligaments and tendons involves the placement of suture anchors in the underlying bone so that the particular ligament or tendon can be reattached to the bone through the use of sutures. Historically, this procedure was accomplished through invasive surgery requiring extended hospitalization, etc. However, the fairly recent advances in arthroscopic surgical techniques have practically eliminated the need for invasive surgery for ligament and tendon repair. The corresponding result from this kind of surgery is that it is now routinely conducted on an outpatient basis. The beneficial result is a significant decrease in the trauma to the patient, a shorter recovery period, reduced scarring, lower costs, and the like.
The current practice of ligament or tendon reattachment involves the implantation of a plurality of suture anchors in the bone at preselected positions relative to the original attachment site of ligament or tendon to the bone. Implantation of the suture anchor customarily requires a hole drilled into the bone to receive the suture anchor. The hole is prepared with a prescribed depth and is drilled with a bone drill having a preselected diameter to produce a hole having the appropriate dimensions. The anchor is embedded in the hole and the ligament or tendon is then secured to the suture anchor using appropriate suturing techniques.
Other surgical procedures involve drilling a plurality of spaced holes in bone for the purpose of increasing the blood supply to that particular area of the bone. However, I have found that the operation of a conventional rotating drill bit near exposed tissue, particularly that encountered in the close confines of an arthroscopic procedure, frequently results in loose ends of the exposed tissue becoming entangled by the rotating drill bit. Another problem I have encountered in my practice as an orthopedic surgeon is that it is extremely difficult to precisely position a hole drilled in a curved surface of the bone, particularly during certain surgical procedures involving the repair of injuries to the knee and the shoulder. This difficulty results from the tip of the drill bit slipping across the curved surface of the bone as the drill is rotated. This problem is especially acute when the hole to be drilled is oriented at an angle other than 90 degrees to the bone surface. A further problem I have encountered in my practice is the production of bone residue that remains after the drilling procedure has been completed.
In view of the foregoing, it would be an advancement in the art to provide a shield for the bone drill apparatus and method whereby the bone drill is shielded to preclude loose tissue from becoming entangled with the rotating bone drill. Another advancement would be to provide a guide for the bone drill, the guide providing a securement mechanism for preventing the tip of the bone drill from slipping across the surface of the bone. An even further advancement would be to provide a bone drill having an evacuation system for removing debris generated during the drilling procedure. Another advancement would be to provide a depth limiting system for controlling or otherwise limiting the depth to which the bone drill is able to penetrate the bone. Another advancement would be to provide a depth gauge as part of the shield to enable the surgeon to determine the depth of penetration of the bone drill into the bone. Another advancement would be to provide an asymmetric tip to the shield as an assist in inserting the bone drill through the tissue and to more securely anchor the tip of the shield to the bone to more accurately position the drill bit against the bone. Such a novel apparatus and method is disclosed and claimed herein.